Introduction to Coordinate Geometry

A web page that introduces the concepts behind coordinate geometry. Can be used as a reference for students to learn about the topic when away from class. Has links to other related pages that contain animated demonstrations. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Intersecting straight lines. (Coordinate Geometry)

An interactive applet and associated web page that show how to find the intersection of two straight lines, given the equation for each. The applet sows two lines defined by two pairs draggable points. As any point is dragged the equations for the lines are derived and the point of intersection calculated. The web page shows worked examples using various line slopes, equation forms and unusual conditions, such as one line being vertical. The grid, axis pointers and coordinates can be turned on a

Intercept (b) of a line (Coordinate Geometry)

An interactive applet and associated web page that demonstrate the intercept (b) of a line. The applet has two points that define a line. As the user drags either point it continuously recalculates the intercept, the point where the line crosses the y-axis at x=0. Can be used in conjunction with the slope to derive the equation of a line. The grid, axis pointers and coordinates can be turned on and off. The intercept calculation can be turned off to permit class exercises and then turned back on

Horizontal line definition. (Coordinate Geometry)

An interactive applet and associated web page that show the definition of a horizontal line in coordinate geometry. The applet has two points that the user can drag which define a line. The line flagged when it is horizontal (slope=0) and the equation of the line is shown. The grid, details and coordinates can be turned on and off. The applet can be printed exactly as it appears on the screen to make handouts. The web page has a discussion on how to test for horizontal, the line equation and has

Equation of a line - point - slope form. (Coordinate Geometry)

An interactive applet and associated web page that demonstrate the equation of a line in point-slope form. The user can move a slider that controls the slope, and can drag the point that defines the line. The graph changes accordingly and equation for the line is continuously recalculated with every slider and / or point move. The grid, axis pointers and coordinates can be turned on and off. The equation display can be turned off to permit class exercises and then turned back on the verify the a

Equation of a line - slope and intercept form. (Coordinate Geometry)

An interactive applet and associated web page that demonstrate the equation of a line in coordinate geometry. The equation is in the form y=mx+b. The user can move two sliders that control a and b. The graph changes accordingly and equation for the line is continuously recalculated with every slider move. The grid, axis pointers and coordinates can be turned on and off. The equation display can be turned off to permit class exercises and then turned back on the verify the answers. The applet can

Distance between points

An interactive applet and associated web page that demonstrate how to find the distance between two points with given coordinates. The applet has two points on a Cartesian plane. As the user drags either point it continuously recalculates the distance between them. The distance is shown both on the plane and as a continuously changing formula. The grid, axis pointers and coordinates can be turned on and off. The distance calculation can be turned off to permit class exercises and then turned bac

Circumscribed rectangle, bounding box. (Coordinate Geometry)

An interactive applet and associated web page that show the definition and properties of the bounding box of a polygon or set of points. The bounding box is used in other entries to find area using the so-called box method. The grid, coordinates and calculations can be turned on and off for class problem solving. The applet can be printed in the state it appears on the screen to make handouts. The web page has a full definition of a bounding box when the coordinates of the points defining it are

Print blank graph paper

A page that allows you to print rectangular (cartesian) graph paper. You ca control if grid lines are printed and the position of the origin. By dargging the origin into any corner a single quadrant can be printed. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Constructing the Incenter of a triangle

An interactive applet and associated web page that provide step-by-step animated instructions on how to construct the incenter of a triangle. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Finding the foci an ellipse

An interactive applet and associated web page that provide step-by-step instructions on how to find the foci of a given ellipse using a compass. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Constructing circumcenter of a triangle with compass and straightedge

An interactive applet and associated web page that provide step-by-step animated instructions on how to construct the circumcenter of a triangle. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Constructing a 90 degree angle with compass and straightedge

An interactive applet and associated web page that show how to construct a 90 degrees right angle with a compass and straightedge. The animation can be single-stepped or run as a continuous movie. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

SSA doesn't work

An interactive applet and associated web page that shows that side-side-angle is not enough to prove congruence, because two triangles can meet the condition. The applet shows two triangles, one of which can flip between the two possible configurations that both meet the SSA criteria, showing it is insufficient. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the M

Congruent Polygons

An interactive applet and associated web page that demonstrate the congruence of polygons. The applet presents nine polygons that are in fact congruent, but don't look it because they are reflected and rotated in various ways. If you click on one, it rotates and flips as needed, then slides over the top of another to show it is congruent. The web page describes how to determine if two polygons are congruent. Applet can be enlarged to full screen size for use with a classroom projector. This reso

AAA Doesn't work

An interactive applet and associated web page that shows that angle-angle-angle (AAA) is not enough to prove congruence. The applet shows two triangles, one of which can be dragged to resize it, showing that although they have the same angles they are not the same size and thus not congruent. The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference I

Radius of an Arc or Segment

An interactive applet and associated web page that describe the radius of an arc and how to derive it from the width and height of the segment defined by that arc. A practical use is described for finding the radius of a circular arch given its other dimensions. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Perimeter of a triangle

A web page and interactive applet show how to compute the perimeter of a triangle. A triangle is shown that can be resized by dragging its vertices. As you drag, the perimeter is continuously recalculated. Text on the page explains that the perimeter is the sum of the sides. For those who prefer it, in a formula that is given. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference interactive geometry reference book

Readings in the History of Aesthetics

Anyone with connection to the Internet has access to a vast number of philosophical documents via online etexts. Fortunately, quite a bit of the best work in philosophy is in the public domain, and a few of these readings provide a convenient access for almost anyone seeking information and help in the history of aesthetics. However, many of the historically significant writings in aesthetics are not presently available on the Internet, and this open source text helps somewhat to remedy that nee

Readings in Eastern Philosophy

Many classic works in Eastern philosophy are accessible via online sources on the Internet. Fortunately, many of the influential and abiding works are in the public domain; these readings provide a convenient way to produce quality learning experiences for almost anyone seeking information and help. Our present collection of edited readings is free but subject to the legal notice following the title page. By placing these selections in the public domain under the GFDL, the editors are, in effect